In order to watch a currently distributed HD 3D LCD TV, it is required to use special glasses. In order to embody a UD 3D LCD TV without needing to use such glasses, an image-driving speed needs to be increased from a current speed level of about 240 Hz to about 480 Hz.
To increase the image-driving speed to the required level, it may be essential to use an amorphous/crystalline oxide semiconductor thin film transistor (TFT), which features a highly improved speed, as compared to an amorphous silicon-based TFT having low electron mobility.
Required to manufacture such an oxide semiconductor TFT are a patterning technique for oxide semiconductor and an etching technique having a high selectivity between the oxide semiconductor and a data wiring structure formed thereon.
However, the oxide semiconductor is easily dissoluble in acid. Accordingly, if wet etching is performed when etching the data wiring structure on the oxide semiconductor, the oxide semiconductor may be dissolved in a solution used for the wet etching. Thus, it has been difficult to adjust the selectivity between the oxide semiconductor and the data wiring structure.
To resolve the problem, there is known a method for dry-etching the data wiring structure. A conventional thin film transistor is illustrated in FIG. 1. A gate electrode 21 and a gate insulating layer 20 are formed on a substrate having a SiOx film 15 deposited thereon. An oxide semiconductor 30 and a wiring structure 40 are deposited on the gate insulating layer 20 in sequence.
If dry etching is performed on the thin film transistor having the above structure, plasma damage may be inflicted on a surface of the oxide semiconductor 30. To prevent generation of the plasma damage, an etch stopper 50 is formed between the oxide semiconductor 30 and the wiring structure 40, as shown in FIG. 1.
In order to form the etch stopper, however, a photolithography process needs to be additionally performed, resulting in an increase of processing cost and time for the manufacture of the thin film transistor.